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Finding the Fourth Proportional to 857.60, 1,286.49 and 280.34

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Solution

The fourth proportional to 857.60, 1,286.49 and 280.34 is: 420.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.60 : 1,286.49 = 280.34 : x
  2. Step 2: Convert to fraction form
    857.60/1,286.49 = 280.34/x
  3. Step 3: Cross multiply
    857.60x = 1,286.49 × 280.34
  4. Step 4: Simplify right side
    857.60x = 360,654.61
  5. Step 5: Solve for x
    x = 360,654.61/857.60
  6. Step 6: Final answer
    x = 420.54

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.